A total of 2,000 gallons of 70 wt% ethanol in water, having a specific gravity of 0.871, is to be separated at 1 atm in a batch rectifier operating at constant distillate composition with a constant molar vapor boilup rate to obtain a distillate product of 85 mol% ethanol and a residual waste water containing 3 wt% ethanol. If the task is to be completed in 24 h, allowing 4 h for charging, start-up, shutdown, and cleaning, determines:
(a) The number of theoretical plates required in the column,
(b) The reflux ratio when the concentration of ethanol in the pot is 25 mol%,
(c) The instantaneous distillate rate in lbmol/h when the concentration of ethanol in the pot is 15 mol%,
(d) The lbmol of distillate product, and
(e) The lbmol of residual wastewater. Vapor-liquid equilibrium data are given in Exercise 7.29.